530 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



pied by sharp lines in the other spectra the plates at hand give insuffi- 

 cient evidence. A more exact study of these bands and the similar 

 ones in the calcium spectrum offers great interest. 



BARIUM. 



Spark. Barium chloride on carbon electrodes. 



Arc. Barium chloride on carbon electrodes. 



Wehnelt. Platinum point in solution of barium chloride. (Plate 1, Fig. 4.) 



The above comparison table for barium does not include the bands in 

 the green which are strong in the spectrum of the Wehnelt. The follow- 

 ing table gives the approximate position of these bands. 



